# Integration and Testing
source: https://developer.mastercard.com/identity-insights-for-accounts/documentation/tutorials-and-guides/api-testing-tutorial/index.md

### Introduction {#introduction}

In this section, we'll explain how to generate Identity Insights for Accounts API client to use with MTLS-enabled APIs.

### What you will learn {#what-you-will-learn}

* Generate an API client using [OpenAPI Generator](https://openapi-generator.tech/), which provides generators and library templates for supporting multiple languages and frameworks.
* Configure the generated API client to use your certificate for authentication.

### Estimated time to complete this tutorial {#estimated-time-to-complete-this-tutorial}

* 30 minutes

### Prerequisites {#prerequisites}

To complete this tutorial, you will need:

* An IDE of your choice
* Mastercard Developers account with access to the Identity Insights for Accounts API
* Identity Insights for Accounts API OpenAPI Specification (Refer to the [Open Specification](https://developer.mastercard.com/identity-insights-for-accounts/documentation/api-reference/index.md) for details.)

Note: We use Java for code samples in this guide, but OpenAPI Generator supports building clients for most major languages.

## Create an API Project in Mastercard Developers {#create-an-api-project-in-mastercard-developers}

Please refer sandbox tutorial [here](https://developer.mastercard.com/identity-insights-for-accounts/documentation/tutorials-and-guides/sandbox-access-tutorial/index.md) for creating an API.

Refer to the following page for more information on [Using MTLS to Access Mastercard API Client](https://developer.mastercard.com/platform/documentation/security-and-authentication/using-mtls-to-access-mastercard-apis/).

## Download an OpenAPI Specification {#download-an-openapi-specification}

* Access the documentation for the chosen API.
* Click to open the API reference specification page [here](https://developer.mastercard.com/identity-insights-for-accounts/documentation/api-reference/index.md).
* For this tutorial, we'll use the Swagger documentation for the Identity Insights for Accounts API [IIA-swagger-public.yaml](https://static.developer.mastercard.com/content/identity-insights-for-accounts/swagger/IIA-swagger-public.yaml) (30KB)

### Generate an API Client Project {#generate-an-api-client-project}

* Download the OpenAPI Generator CLI (you can follow the instructions [here](https://openapi-generator.tech/docs/installation/))

* Create a `config.json` file with various options for the OpenAPI Generator.

  * Java
  * Python
  * NodeJs
  * C#

  ```Java
  { 
        "groupId" : "com.mastercard.idv",
        "artifactId" : "aii-service-reference-app",
        "artifactVersion" : "0.0.1-SNAPSHOT",
        "invokerPackage" : "com.mastercard.idv",
        "apiPackage" : "com.mastercard.idv.aii"   
  }
  ```

  ```Python
  {}
  ```

  ```NodeJs
  {
    "useES6" : false
  }
  ```

  ```C#
  { 
      "targetFramework" : "netstandard2.1",
      "packageName" : "com.mastercard.idv.tra.Service",
      "packageVersion" : "1.0.0",
      "sourceFolder" : "",
      "netCoreProjectFile": true,
      "modelPropertyNaming":"camelCase",
      "optionalAssemblyInfo": false
  } 
  ```

  <br />

* Execute the following command for the language in which you want the client to be generated (we assume here the `openapi-generator-cli` command is available):

*
  * Java
  * Python
  * NodeJs
  * C#

  ```Java
    openapi-generator-cli generate -g java --library okhttp-gson -i *.yaml -c config.json -o api_client
  ```

  ```Python
  If using openapi generator version >= 5.0.0, use below command to generate the client:
  openapi-generator-cli generate -g python-legacy -i *.yaml -c config.json -o api_client ">

  # If using openapi generator version < 5.0.0, use below command to generate the client:
  openapi-generator-cli generate -g python -i *.yaml -c config.json -o api_client

  # If using openapi generator version >= 5.0.0, use below command to generate the client:
  openapi-generator-cli generate -g python-legacy -i *.yaml -c config.json -o api_client
  ```

  ```NodeJs
  openapi-generator-cli generate -g javascript -i *.yaml -c config.json -o api_client
  ```

  ```C#
  openapi-generator-cli generate -g csharp-netcore -i *.yaml -c config.json -o api_client
  ```

* Look at the `api_client` directory for the generated project

Tip: More options are available. The OpenAPI Generator CLI documentation can be found [here](https://openapi-generator.tech/docs/usage/)

### Create an API Client Instance and Enable Authentication {#create-an-api-client-instance-and-enable-authentication}

1. Create a test project or an application project
2. Create an instance of the generated `ApiClient` class and configure it as below:

* Java

```Java
ApiClient client = new ApiClient();
OkHttpClient.Builder httpClientBuilder = client.getHttpClient().newBuilder();
// Configure the Mastercard service URL
client.setBasePath("https://sandbox.idv.mastercard.com/identity/accounts");
// Load your client certificate
KeyStore pkcs12KeyStore = KeyStore.getInstance("PKCS12");
pkcs12KeyStore.load(new FileInputStream("./path/to/your/client-cert.p12"), "keystorepassword".toCharArray());
// Configure a secure socket
KeyManagerFactory keyManagerFactory = KeyManagerFactory.getInstance(KeyManagerFactory.getDefaultAlgorithm());
keyManagerFactory.init(pkcs12KeyStore, "keystorepassword".toCharArray());
TrustManagerFactory trustManagerFactory = TrustManagerFactory.getInstance(TrustManagerFactory.getDefaultAlgorithm());
trustManagerFactory.init(pkcs12KeyStore);
SSLContext sslContext = SSLContext.getInstance("TLS");
sslContext.init(keyManagerFactory.getKeyManagers(), null, new SecureRandom());
client.setHttpClient(
    httpClientBuilder
        .sslSocketFactory(sslContext.getSocketFactory(), (X509TrustManager) trustManagerFactory.getTrustManagers()[0])
        .build()
);

```

* Replace:   
  * `./path/to/your/client-cert.p12` with the path to your client certificate.
  * `keystorepassword` with the password for your client certificate.
  * `https://sandbox.idv.mastercard.com/identity/accounts` with the actual environment and service path you want to call.

Note: OpenAPI Generator supports several HTTP clients and frameworks for Java (Jersey, OkHttp, RestTemplate, Retrofit). In this guide, we chose to use `okhttp-gson`. Tip: Refer to the [reference app](https://developer.mastercard.com/identity-insights-for-accounts/documentation/reference-app/index.md) for more details.

### Call the Service {#call-the-service}

* Under the src/main/resources/ folder path, create a property file named application.properties.
* To make the API call, you need to make your MTLS credentials available to the program for use

```XML
  Resource jweEncPublicKeyPath = classpath:publicKey.pem;
  String jweClientEncPublicKey = "FingerPrint from mastercard portal";
  String clientside = "classpath:idvhub-test-external-client.mastercard.int.pfx";
  PrivateKey truststore = "classpath:cacerts";
```

* Instantiate a client with your authentication credentials and configuration object as interceptors before you can send it.

* Java

```Java
@Bean(value = "aiiApiClient")
public com.mastercard.idv.serviceaii.ApiClient aiiApiClient()
  throws UnrecoverableKeyException, CertificateException, NoSuchAlgorithmException, KeyStoreException, IOException {

  com.mastercard.idv.serviceaii.ApiClient client = new com.mastercard.idv.serviceaii.ApiClient();
  client.setBasePath(baseUrl);
  client.setHttpClient(createHttpClient(client.getHttpClient()));
  return client;
  }

```

Tip: Refer to the [reference app](https://developer.mastercard.com/identity-insights-for-accounts/documentation/reference-app/index.md) for more details.